Some contributions to the management of data in grids Lionel Brunie National Institute of Applied Science (INSA) LIRIS Laboratory/DRIM Team – UMR CNRS 5205 Lyon, France

2 NDS : Network Distance Service

3 Grid access control: Sygn Mechanisms for delegation of rights File group operations Permission = Authorization Certificate (AC) : – Issuer – Owner – Capability (access control object + authorized action) – Validity – Signature

4 4 Encrypted storage for Data Grids: Crypstore

5 Management of a Cooperative Cache in Grids cache organization GRID data organization data Collective Coordinator Monitoring operations data description processed requests transfers replacements used storage resource Etc. Management operations Set replacement method Set default time to live Set cache group Set cache coordinator Set collective work mode Etc.

6 Data integration

7 Some contributions to Pervasive/Ubiquitous Systems

8 PerSE Adaptation context Models Context-awareness Proactivity Service composition

9 Architecture of a PerSE Base

10 PerSE Layers

11 Context modeling and Context-aware pervasive applications Context = ? User/Application centric Context Context-aware application platform

12 Access Control for mobile users Chains of trust certificates: if A trusts B and B trusts C then A trusts C… to some level Multi-layered adaptive certificates Trust computing and reputation

13 Authentication and Trust in pervasive systems

14 Mobile requests Information exchange between mobile peers (MANETs, VANETs) Trajectory aware geocast request routing Construction for each query of an ad hoc overlay of the peers that may participate to the delivery of the requested data

15 Data replication in small worlds Server Original content

16 Replication in ad hoc networks Issues: instability, dynamicity, faults/disconnections Basic idea: adapt the replication heuristics to the actual usage of the data, e.g.: –Data highly accessed => replicate –Rare data and planned disconnection => replicate –Overloaded peer => replicate most accessed data –Etc. Pre-requisite: access logging + exchange of access data Assumption: no central coordination – local decisions Question : can local decisions lead to an acceptable (good ?) situation ?

17 Interface adaptation and context-aware browsing of a patient medical record

18 Multimedia Content Adaptation + Adaptation of the interface wrt the end-user device Ongoing : Content Adaptation in MANETs

19 Semantic protection of multimedia data Multimedia => access control is not a binary decision Access control content adaptation Coherence/Consistence of an adaptation Legality of an adaptation => Access control = semantic adaptation decision

20 Semantic clustering of multimedia queries: From query logging to database content and user profile discovery Large number of data stores disseminated Lack of indexes Issues : –What are the pertinent/interesting data ? –What are the users interest ? –How to process a query ? Logging of the users’ queries + clustering + communication of clustering info => identification of the community of users’ interests Logging of a the queries issued by a specific user + matching to the community clustering => identification of the user’s profile Usage: query optimization, data store management, recommendation, social computing, etc.